Sender Reputation
A score calculated by ISPs based on sending behavior, affecting inbox placement.
A score calculated by ISPs based on sending behavior, affecting inbox placement.
Why It Matters
Your sender reputation is like a credit score for email—it determines whether ISPs let your emails through to the inbox or filter them to spam. Built over time through good sending practices, reputation is hard to earn and easy to damage. A poor reputation can take months to rebuild.
Practical Example
Scenario
A wellness brand checks Google Postmaster Tools and sees their domain reputation dropped from 'High' to 'Medium' after a promotional blast to an old segment.
Calculation
Spam complaints spiked to 0.4% on that campaign vs their usual 0.05%Result
They immediately stop sending to unengaged segments, clean their list, and focus on highly engaged subscribers. After 6 weeks of clean sending, reputation recovers to 'High'.
Pro Tips
- 1Monitor reputation with Google Postmaster Tools, Microsoft SNDS, and your ESP's deliverability dashboard
- 2Maintain consistent sending volume—sudden spikes trigger ISP suspicion
- 3Keep spam complaints under 0.1% and bounces under 2%
- 4Warm up new IPs/domains gradually before high-volume sending